字符串-进制转换模板

string Reverse(string s,int m,int n) {
    string ret = "";
    int len = s.size();
    for(int i = 0;i < len;) {
        int k = 0;
        for(int j = 0;j < len;j++) {
            int t = (k*m+s[j]-'0')%n;
            s[j] = (k*m+s[j]-'0')/n+'0';
            k = t;
        }
        ret+=(k+'0');
        while(s[i]=='0') i++;
    } 
    return ret;
}